Ehf array antenna backplate including radiating modules, cavities, and distributor supported thereon

Abstract

An EHF array antenna backplate that integrates thermal cooling structure and signal processing structure together into one unified structure. In one embodiment, forced air is employed to conduct heat from active modules; while in another embodiment, embedded heat pipes are employed. The array backplate is made by using four layers. The layers are: a high density multichip interconnect board, a metal matrix composite motherboard, an integrated waveguide/cavity/cooling structure, and a metal matrix composite baseplate. Each module uses solder bumps to connect to the high density multichip interconnect board where DC power and control logic signal distribution takes place. The modules are soldered in four locations to the metal matrix composite motherboard through openings in the high density multichip interconnect board. EHF signals are coupled to the modules from a resonant cavity via probes that protrude through the high density multichip interconnect board. Probes are strategically located in the resonant cavity to pick up an EHF standing wave generated by slots that are part of a slotted planar waveguide EHF 16-way power divider network. The waveguide/cavity/cooling structure is also the primary load-bearing member of the backplate.

What is claim is: 
     
       1. An EHF band wave distributor comprising first and second layers, the first layer comprising:   a two dimensional array of subarray modules; and   a plurality of probes, each probe being associated with a respective subarray module; and   the second layer comprising:   a two dimensional array of resonant cavities for supporting standing waves, each cavity being associated with a respective subarray module;   a waveguide network for distributing EHF energy;   a plurality of slots disposed between the cavities and the network for electromagnetically communicating the EHF energy from the network to each respective cavity thereby establishing a standing wave in each respective cavity; and   a plurality of radiating elements each element being associated with a respective subarray module, wherein each probe extends into a respective cavity for electromagnetically coupling the respective radiating element to the standing wave within the respective cavity.   
     
     
       2. The distributor of claim 1 further comprising a fifth layer disposed between the resonant cavities and the subarray modules for providing interconnections between the subarray modules and external power and control signals. 
     
     
       3. The distributor of claim 1 further comprising a third layer comprising a sheet of metal matrix composite for providing a top cover for the resonant cavities through which cover the probes extend to electromagnetically couple each respective radiating element to the standing waves within each respective cavity. 
     
     
       4. The distributor of claim 1 further comprising a fourth layer comprising a metal matrix composite sheet for providing a bottom cover for the distributor. 
     
     
       5. The distributor of claim 1 wherein the second layer further defines a network of cooling fluid channels disposed adjacent the resonant cavities. 
     
     
       6. The distributor of claim 5 further comprising a third layer comprising a metal matrix composite sheet for providing a bottom cover for the distributor and for defining a bottom wall of the cooling channels. 
     
     
       7. The distributor of claim 1 further comprising an array of heat pipes associated with said first and second layers for conducting heat away from the resonant cavities. 
     
     
       8. The distributor of claim 7 wherein the heat pipes are disposed between the first and second layers. 
     
     
       9. A multiple layer EHF band wave distributor comprising: a first layer comprising a metal matrix composite motherboard for providing structural rigidity and heat conduction for the multiple layer distributor;   a second layer disposed below the first layer comprising a resonant cavity, means for cooling the distributor thermally coupled to the cavity and a non-physical resonator-fed wave distribution system having waveguide slots for electromagnetically coupling waves in the distribution system into the cavity; and   a third layer disposed below the second layer comprising a metal matrix composite baseplate that provides a bottom cover for the distributor.   
     
     
       10. The distributor of claim 9 further comprising a fourth layer disposed proximate the first layer having an array of subarray modules containing coupling probes for electromagnetically coupling respective radiating elements to the cavity. 
     
     
       11. The distributor of claim 10 further comprising a fifth layer disposed above the first layer and comprising a high density interconnect layer for providing DC power and control logic signals to the subarray modules. 
     
     
       12. The distributor of claim 9 wherein the cooling means comprises an array of heat pipes disposed adjacent the resonant cavity. 
     
     
       13. The distributor of claim 9 wherein the cooling means comprises a network of cooling fluid channels below the resonant cavity and above the third layer for conducting cooling fluid about the distributor. 
     
     
       14. The distributor of claim 13 further comprising a plurality of holes in the resonant cavity for conducting cooling fluid between the cavity and the cooling fluid channels. 
     
     
       15. The distributor of claim 13 wherein at least a portion of the cooling fluid channels are contiguous with a wall of the cavity. 
     
     
       16. The distributor of claim 9 wherein the cavity comprises a plurality of resonant cavities defined by the second layer and arranged as adjacent rectangles to form a two dimensional grid of cavities. 
     
     
       17. An EHF band wave distributor comprising: a plurality of resonant cavities, each cavity having at least a floor and a cover;   a network of waveguides disposed below the floors, each waveguide being fed by a single source of radiation;   a plurality of slots in the floor of each cavity, the slots being in electromagnetic communication with the waveguides for establishing a predetermined standing wave pattern in each respective cavity;   a plurality of coupling probes protruding through the cover of each cavity, each probe electromagnetically coupling a respective radiating element to the standing wave pattern in a corresponding cavity.   
     
     
       18. The distributor of claim 17 wherein the cavities are arranged as adjacent rectangles to form a two dimensional grid of cavities. 
     
     
       19. The distributor of claim 18 wherein the adjacent rectangles abut one another. 
     
     
       20. The distributor of claim 18 wherein the grid comprises four cavities in each of the two dimensions of the grid for a total of sixteen cavities. 
     
     
       21. The distributor of claim 17 further comprising an array of subarray modules, each module corresponding to a different one of the cavities, each module containing a portion of the coupling probes. 
     
     
       22. The distributor of claim 21 wherein each subarray modules has a direct solder connection to the respective cavity cover through which its respective coupling probes extend. 
     
     
       23. The distributor of claim 21 wherein each subarray module contains sixteen coupling probes. 
     
     
       24. The distributor of claim 17 wherein the cavity covers comprise a single metal matrix composite sheet. 
     
     
       25. The distributor of claim 17 further comprising means, associated with the resonant cavities for cooling the resonant cavities. 
     
     
       26. The distributor of claim 25 wherein the cooling means comprises a network of cooling fluid channels below the floors of the cavities for conducting cooling fluid about the distributor. 
     
     
       27. The cooling means of claim 26 further comprising a plurality of holes in the cavity floors for conducting cooling fluid between the cavities and the cooling fluid channels. 
     
     
       28. The cooling means of claim 26 wherein at least a portion of the cooling fluid channels are contiguous with the cavity floors. 
     
     
       29. The distributor of claim 26 wherein the cooling fluid comprises air. 
     
     
       30. The distributor of claim 25 wherein the cooling means comprises an array of heat pipes disposed adjacent the resonant cavities.